AdViewForListViewWrapperAdapter.java

package com.smartsoft.library.adapters;

import android.app.Activity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdSize;
import com.google.android.gms.ads.AdView;

/**
 * Shows ads every K items in ListView
 */
public class AdViewForListViewWrapperAdapter extends BaseAdapter {
    private static final int SHOW_AD_EVERY_K_ITEMS = 5;

    private final Activity    activity;
    private final BaseAdapter delegate;
    private final String      adMobId;

    public AdViewForListViewWrapperAdapter(Activity activity, BaseAdapter delegate, String adMobId) {
        this.activity = activity;
        this.delegate = delegate;
        this.adMobId = adMobId;
    }

    @Override
    public int getCount() {
        // Total count includes list items and ads.
        return delegate.getCount();
    }

    @Override
    public Object getItem(int position) {
        // Return null if an item is an ad.  Otherwise return the delegate item.
        if (isItemAnAd(position)) {
            return null;
        }
        return delegate.getItem(getOffsetPosition(position));
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (isItemAnAd(position)) {
            if (convertView instanceof AdView) {
                return convertView;
            } else {
                AdView adView = new AdView(activity);

                adView.setAdSize(AdSize.BANNER);
                adView.setAdUnitId(adMobId);

                AdRequest adRequest = new AdRequest.Builder()
                                              .addTestDevice(AdRequest.DEVICE_ID_EMULATOR)
                                              .build();

                adView.loadAd(adRequest);

                return adView;
            }
        } else {
            return delegate.getView(getOffsetPosition(position), convertView, parent);
        }
    }

    @Override
    public int getViewTypeCount() {
        return delegate.getViewTypeCount() + 1;
    }

    @Override
    public int getItemViewType(int position) {
        if (isItemAnAd(position)) {
            return delegate.getViewTypeCount();
        } else {
            return delegate.getItemViewType(getOffsetPosition(position));
        }
    }

    @Override
    public boolean areAllItemsEnabled() {
        return false;
    }

    @Override
    public boolean isEnabled(int position) {
        return (!isItemAnAd(position)) && delegate.isEnabled(getOffsetPosition(position));
    }

    private boolean isItemAnAd(int position) {
        return (position % SHOW_AD_EVERY_K_ITEMS) == 0;
    }

    private int getOffsetPosition(int position) {
        return position;
    }
}